You more that likely have XP set to automatically reboot when it BSODs. To disable this, go to control panel > system > Advanced > Startup and recovery > uncheck automatically restart, set your Write Debugging Information to Small Memory Dump or None, your choice.

Send back the BSOD message so we can troubleshoot it. It may also be in your Event Log in the Administrative Tools.

I had that problem under XP for a while, I discovered it was a clash of drivers between my iWill card drivers, and the Sound Blaster Platinum software (not the drivers). When I uninstalled the software, leaving just the SB Plat. drivers, the problem went away. Try using the 4 in 1 from the VIA site, and generally update all the other drivers.